Embodiments of the present disclosure relate to a fuel conversion system, and more particularly to a syngas production system used in such fuel conversion system.
With increased availability and stable prices of natural gas (NG), there is greater emphasis on using such fuels to effectively convert such fuels into alternative fuels. Gas to Liquid (GTL) technologies become one such viable option to produce liquid fuels from the NG. This option is of even greater importance with the world-wide drive to reduce NG flaring from oil production. Until recently GTL on small scale was not considered economical due to the high capital expenditure (CAPEX) and technical challenges with the technology scaling down.
In GTL systems syngas production sub-systems are used to produce a gas stream containing hydrogen and carbon monoxide (hereinafter also referred as “syngas”) from conventional fuels such as natural gas, coal, and biomass. The syngas production systems may include gasifiers, steam reformers, and the like. Syngas production contributes ˜40% to the total cost of medium scale and ˜60% to the cost of small-scale GTL plants.
This disclosure is related to syngas production using fuel-rich NG combustion in an internal combustion engine using oxygen enriched air or pure oxygen as an oxidizer.
When diesel and gasoline are produced from syngas, an optimum ratio of H2:CO in the syngas is 2:1. If the H2:CO ratio is less than 2:1, some amount of CO will not be converted to liquid products. To produce syngas with the desired H2:CO ratio, a GTL system engine would have to operate at Phi=3. Typically, combustion time in a spark ignition engine is limited to a few milliseconds. This residence time may not be sufficient for complete natural gas conversion to syngas. As a result, exiting engine syngas may have a H2:CO ratio of less than 2:1.
Accordingly, there is a need for an improved syngas production system and an associated method for generating syngas with a desired H2:CO ratio.